Multi-phase pressure gas insulated metal enclosed switch plant

ABSTRACT

A pressurized gas insulated switchgear panel includes a pressurized gas chamber enclosing a three-phase bus bar, to which are connected single-phase outlets. Each outlet is divided in succession into a first gas-pressurized isolating switch chamber, a low-pressure chamber and a correlated high-pressure chamber for the phase circuit breaker, a gas-pressurized voltage transformer chamber, a second gas-pressurized isolating switch chamber and finally a further gas-pressurized chamber housing the ground and cable connections. A gas circulating plant including a pump has its high pressure, outlet side connected to the gas chamber enclosing the three-phase bus bar and its low pressure, inlet side connected to the outlet from the ground chambers.

United States Patent Schmitz et a1.

[54] MULTI-PHASE PRESSURE GAS INSULATED METAL ENCLOSED SWITCH PLANT [72]inventors: Wolfgang Schmitz, Birkenau; Gerhard Korner, Schriesheim,.both of Germany [73] Assignee: Aktiengsellschaft Brown Boveri &

Cie, Baden, Switzerland [22] Filed: May 18, 1970 [21] Appl. No.: 38,229

[30] Foreign Application Priority Data May 30, 1969 Germany ..P 19 27561.7

[56] References Cited UNITED STATES PATENTS 3,129,309 4/1964McKeough'etal. ..200/148B 3,230,293 1/1966 Turgeon ..317/l00X 51 Aug. 1,1972 Primary Examiner-Robert S. Macon Attorney-Pierce, Schefiler &Parker 5 7] ABSTRACT A pressurized gas insulated switchgear panelincludes a pressurized gas chamber enclosing a three-phase bus bar, towhich are connected single-phase outlets. Each outlet is divided insuccession into a first gas-pressurized isolating switch chamber, alow-pressure chamber and a correlated high-pressure chamber for thephase circuit breaker, a gas-pressurized voltage transformer chamber, asecond gas-pressurized isolating switch chamber and finally a furthergas-pressurized chamber housing the ground and cable connections. A gascirculating plant including a pump has its high pressure, outlet sideconnected to the gas chamber enclosing the three-phase bus bar and itslow pressure, inlet side connected to the outlet from the groundchambers.

11 Claims, 3 Drawing Figures PATENTEDAUB 1 I972 3.681.549

SHEET 2 BF 3 amen (01o Wolfgang SQHmhSL Gerhard korner w! PM L AXS PmPATENTEDAUQ 1 1912 3,681. 549

sum 3 or 3 3mm Wolfgang Schmiiz Ge rhard korne r scaxggzux may I mmMULTI-PHASE PRESSURE GAS INSULATED METAL ENCLOSED SWITCH PLANT Inaccordance with one embodiment, three separate gas paths may beestablished respectively from the gas chamber enclosing the three-phasebus bar through the isolating switch chambers, voltage transformerchamber and ground chamber of each single-phase outlet to the inlet sideof the pump. According to a second embodiment, one continuous gas pathis established from the gas chamber enclosing the three-phase bus barthrough the first isolating switch chambers in series, thence throughthe voltage transformer chambers in series, thence through the secondisolating switch chambers in series and thence through the groundchambers in series to the inlet side of the pump. Relief, i.e., onewayvalves are interposed in the gas connections in the series between thevarious chambers.

The high and low pressure gas chambers associated with the respectivephase circuit breakers are supplied with the necessary pressurized gasfrom the pump, or other source through separate circuits.

This invention relates to a multiphase, pressure-gas insulated,metal-enclosed switch plant with singlephase outlets. A metal-enclosed,gas pressurized, bus bar chamber contains the bus bars for all phasesand single phase outlets are connected to the bus bar chamber. Eachoutlet, comprises a row of metal-enclosed gas pressurized chamberscontaining the power circuit breaker for the phase and related operatingcomponents such as an isolating switch, voltage transformers and groundand cable connections, each housed within a separate chamber andseriately connected between the appertaining bus bar and the phaseoutlet terminal.

The subdivision into individual gas pressurized chambers is effected sothat any troubles of an electrical nature as well as troubles, which maybe caused by gas impurities or leakage losses, cannot afi'ect the entireplant, and it is thus possible to remove individual operating componentsseparately from the switch plant for inspection, without having to stopthe entire plant and making it gas-free. The subdivision into individualgas pressurized chambers requires, however, a complicated pressuremonitoring system for the individual gas pressurized chambers whichnecessitates a great number of pressure monitors or gas density monitorsand possibly the connection of several additional gas cylinders for thegas supply.

The object of the invention is to permit a gas supply to these gaschambers in such switch plants while maintaining the sectioning intoindividual gas pressurized chambers, which reduces the risk ofcontamination of individual gas pressurized chambers and which extendsthe time intervals for a general overhaul and replenishment of gas, andwhich also simplifies the monitoring of the pressure in the individualchambers.

This problem is solved according to the invention in switch plants ofthe above-mentioned type by connecting the sectionalized gas chambers ofa switchgear panel over pressure gas lines and/or valves in such a waythat, when a first gas chamber is connected to a common gas supply forall gas chambers, a gas chamber row is formed which can only betraversed in one direction.

The advantage achieved with the invention lies particularly in the factthat the inlet and the outlet of the gas chamber row can be connected bya gas-circulating plant consisting substantially of a pump, filter, anddehumidifier. In addition to the central filling of all gas chamberscombined to a row, it is thus possible to circulate the gas contained inthe chambers continuously or intermittently according to therequirements. This circulation of gas is effected over filters anddehumidifiers, so that the risk of contamination or excessive moisturecontent is reduced to a minimum. A particu- -lar advantage is that thisgas circulation can also be effected during the operation without anyeffect on the operation of the switch plant. Depending on therequirements, a permanent installed gas circulating plant can be usedfor this purposeor a mobile plant which is only connected in spacialintervals. It also provides the possibility of an extremely simplepressure indication for all gas chambers, which can be effected at theend of the gas chamber row by means of a flowmeter. For checking the gassupply it suffices to start the gas flow through the gas chamber row,and the flowmeter provides information about the gas supply of all gaschambers. Individual monitoring of the gas chambers is thus notnecessary. When the operation is started, only this one flowmeter has tobe checked, instead of the pressure manometers which would otherwise berequired for each individual gas chamber.

The gas chamber row of all gas chambers of a switchgear plant accordingto the invention can preferably be subdivided in a further developmentof the invention into individual sections which comprise the gaschambers of the operating components of like function of all phases, theadjoining sections being connected over restrictors and/or valves insuch a way that with a sudden pressure difference between the sectionscaused by a breakdown, the pressure equilibrium can only be establishedwith delay. For particularly comfortable switch plants, automaticshut-off valves can be provided between the sections which arecontrolled by pressure monitors in the individual sections, that is,with a sudden pressure loss in one section, the respective pressuremonitor controls the shut-off valve arranged in this section and selectsthis way the fault.

The invention benefits from the fact that the switchgear panels of theseswitch plants are very compact and that the enclosing sections of theindividual phases of a switchgear panel are very close together so thatthe connection of the individual gas chambers over valves or pipefittings presents no difficulties. For this reason the individual phasesof a switchgear can be easily combined in their functions, that is, thesinglepole installation of the switchgears used in open air switchplants is not of importance in fully enclosed switch plants, but anembodiment is preferred which is encased individually with regard tophase but combined to a multiphase switchgear with regard to functron.

If the combination of the gas chambers of the individual phases of amultiphase switchgear on the basis of the single-pole installation ofconventional switch plants is not desired, that is, if each phase is tobe possibly self-sufficient, a combination of the individual gaschambers of a phase can be readily realized according to the invention.The gas chambers of a phase form a separate gas chamber row, and theparallel-connected gas chamber rows of the individual phases of aswitchgear panel have a common inlet and a common outlet. The flow-meteris then arranged preferably at the end of each gas chamber row, sinceonly this way a reliable reading about the pressure supply of all phasescan be obtained. When the gas circulation starts, it can be seen on eachflowmeter whether the gas is circulated uniformly in all phases.

Since it is common in a multipanel switch plant, for reasons of cost, todivide the bus bar corresponding to the individual connected switchgearpanels into sections, it may be advisable under certain circumstancesnot to include the gas chamber of the bus bar in the gas chamber rowaccording to the invention, but to connect it to a separate gas supply.This somewhat more complicated construction results from an increasedneed for safety, where the bus bars are not to be included in the gascycle of the individual devices, which can naturally not be astrouble-free as the bus bar itself. On the other hand, the gas chamberof the bus bar extending over several switchgear panels as a common gasline for the connection of the gas chamber rows of the individual panelsrepresents an arrangement which is particularly recommended for low-costswitch plants.

If gas blast switches with a separate gas cycle, consisting of a highpressure part and a low-pressure part, are used in the switch plants,the gas supply of the switch will in general not be combined with thatof the remaining switch plant, because the gas blast switch requiresconstant readiness, which necessitates a separate supply and monitoringof the pressure gas, adapted to the conditions of the switch. It may beof advantage, however, to effect the gas-circulation according to theinvention in the gas chambers of a switchgear panel combined to a gaschamber row by the compressor, which is anyway required for the gasblast switch. The compressor of the gas blast switch can be connected,for example, over electromagnetic valves to the inlet or outlet of thegas chamber row. Here a control is recommended which gives preference atany rate to the gas cycle of the gas blast switch, that is, thecompressor switched for gas circulation to the gas chamber row of theswitchgear panel must be switched back immediately to the gas cycle ofthe switch when the pressure difi'erence between the high-pressure partand the low-pressure becomes too low there.

An embodiment of the invention is represented in the drawing and will bedescribed more fully below.

FIG. 1 shows in a schematic representation a threephase switchgear panelwhose individual gas chambers, with the exception of the chamberscomprising the gas blast switch, are combined to a gas chamber row.

FIG. 2 shows a three-phase switchgear panel where the gas chambers of aphase form each a separate gas 4. sively into an isolating switchchamber R3, S3, T3, a low-pressure chamber R4, S4, T4 and ahigh-pressure chamber R5, S5, T5 of the circuit breaker Rl, SL, TL, avoltage transformer chamber R6, S6, T6, another isolating switch chamberR7, S7, T7 as well as a chamber for the ground -and cable terminal R8,S8, T8.

According to the invention, the gas chambers of the switchgear panel areconnected with each other over valves V1, V2, V3, V4 and pressure gaspipe fittings L to a gas chamber row. According to FIG. 1, starting fromgas chamber 1 of the three-phase bus bar, are connected over a one-wayvalve V] the three isolating switch chambers in the order T3, S3, R3,then over another one-way valve V2 the voltage transformer chambers R6,S6, T6. .Then follow over one-way valve V3 the isolating switchor groundchambers, again in the order T7, S7, R7; and finally over anotherone-way valve V4 the chambers of the ground-and cable terminals R8, S8,T8. Excepted from this gas chamber row are merely the gas chambers R4,S4, T4 and R5, S5, T5 which represent the highand low-pressured parts ofthe circuit breaker and thus must have their own gas supply. Theconnection and the entrance respectively into the gas chamber row thusformed is efiected at valve VA, while the outlet is formed by valve VE.Ahead of the valve VB is arranged a flowmeter D so that, when valve VBis opened briefly, a reading appears immediately showing whether all gaschambers 1, R1 T8 are supplied with pressure gas. Of great importance isalso the fact that a gascirculating plant U, consisting of pump P,filter F and dehumidifier E, can be arranged between the connectingvalve VA and the end valve VE. This gas-circulating plant U can beeither permanently connected (see FIG. 2) or it can be designed as amobile gas circulating plantso that the connection can be effected incertain intervals. The valves VA and VE are then designed ascorresponding connection points, this being shown schematically in FIG.1.

Characteristic of the example according to FIG. 1 is also the fact thatthe three operating components with the same function, for example, R3,S3, T3 or R6, S6, T6 of the three phases are combined to a continuoussection in the gas chamber row and that each section is separated fromthe following by a one-way valve Vl V4. This has the result that theoperating components of the three phases belonging together also form aunit with regard to the pressure gas, which is of importance, in case oftrouble, for the inspection and disassembly, if necessary of theswitchgears. In certain cases it may be advisable to use magnetic valvesinstead of the one-way valves so that the gas-connection between thesections can be completely interrupted, if necessary. But a certain gasseparation can also be effected by providing, instead of the valves V1V4, simple restrictors which permit an equalization of gas between thesections only over a longer period. The gas circulation and pressurereading are not affected by it, but with a sudden pressure drop in onesection the pressure equalization takes so long that the countermeasuresnecessary in this case can be taken. The design of the connection pointsG of the gas connecting lines L as instantaneous couplings, for example,permits also any desired bridging of individual sections or gas chambersby flexible gas lines, so that the gas circulation through the remaininggas chamber row is maintained when individual instruments have to beinspected.

FIG. 2 shows how the individual gas chambers of each phase RA, SA, TAcan form a separate gas chamber row'in a principally similar switchplant, as it is represented in FIG. 1. Starting from the gas chamber 1of the bus bar, the gas chambers R3, R6, R7 and R8 are connected overthe pipe fittings L as a separate gas chamber row, S3, S6, S7, S8, andT3, T6, T7 and T8 likewise each as a separate gas row chamber. Thepressure gas circuit breaker arranged in the two gas chambers R4, R5,S4, S5 and T4, T5 respectively was again not included in the gas chamberrow. The three gas chamber rows are provided each with a flowmeter D andthen combined over valve VE with the permanently installed gascirculating plant, which is arranged with the other side at the inletvalve VA. When the gas circulation starts, a reliable reading is againobtained about the gas supply in all three phases. In a variation of theembodiment according to FIG. 1, no one-way valves are used here betweenthe individual gas chambers but magnetic shut-off valves M1, M2, M3 havebeen provided between the isolating switch chambers R3, S3, T3 and thevoltage transformer chambers R6, S6, T6 which can be automaticallycontrolled over pressure monitors (not represented) or at will. Thus,for example, the gas chambers of the voltage transformers R6, S6, T6 canbe separated completely from the other gas chambers of the switchgearpanel. The pipe fittings L have a sufficient throttling efiect so thatthe pressure equilibrium between the individual chambers can again beestablished only with delay, and the sectioning between the individualgas chambers maintains its effect. The embodiment according to FIG. 2will be used when switch plants with possibly self-sufficient phases arerequired.

FIG. 3 finally shows how-the gas chamber row already described in FIG. 1can be combined with the gas pressure supply and the pressure gas cycleof the gas blast switch. The gas chamber row between the inlet valveVAand the end valve VB is identical with that according to FIG. 1. For thepressure gas supply of the circuit breaker LR, LS, LT, a pressure-gasstorage Sp is provided here, to which are connected over various shutoffvalves V5, V6, V7 and a reducing valve VRI the gas chambers R5, S5, T5comprising the high-pressure part. During switching operation, the gasof the high-pressure part flows over the switching zones of the circuitbreaker into the gas chambers R4, S4, T4 which form the low-pressurepart of the circuit breaker. The low-pressure part is then connectedover the valves V8, V9, V10 and a filter F with the low-pressure side ofa compressor K which pumps the gas from the low-pressure part over aone-way valve V11 back into the storage Sp or directly into the gaschambers R5, S5, T5 of the high-pressure part. In order not tojeopardize the gas supply in the low-pressure part of the circuitbreakers, the low pressure gas chambers R4, S4, T4 are connected withthe storage Sp, over a reducing valve VR2 set to the rated pressure ofthe low-pressure part, so that the pressure gas can also flow, ifnecessary, from the storage Sp directly into the chambers R4, S4, T4.

According to the invention, the gas supply of the gas chambers l, R3..T8forming the gas chamber row is coupled with the above described gassupply of the circuit breaker, the inlet valve VA of the gas chamber rowbeing arranged over an additional reducing valve VR3 likewise on the gasstorage Sp, or on the high-pressure side of the compressor K. The end orthe outlet of the gas chamber row, however, is connected over the outletvalve VE with the low-pressure side of the compressor, the outlet sideof the gas chamber row between the two valves V9 and V10 being connectedto the line extending from the low-pressure part of the circuit breaker.It is thus possible to operate selectively by means of the compressors,depending on the position of the valves VA, VE, V7, V8, V9 and V10,either the gas cycle in the circuit breaker the valves V6, V7 V8, V9 andV10 must then be open, or the gas cycle in the gas chamber row 1,R3..Ts, in which case the valves VA, VE, V10 and V6 must be open, whilethe first mentioned valves remain closed.

We claim:

1. A multi-phase, pressure-gas insulated, metal-em closed switchgearplant comprising a metal-enclosed gas-pressurized chamber for the busbar of each phase, single phase outlets electrically connectedrespectively to the corresponding phase bus bar, each said outletcomprising a row of metal-enclosed gas-pressurized chambers containingrespectively the power circuit breaker for the phase and relatedoperating components such as an isolating switch, voltage transformerand cable and ground connections and which are seriately connectedbetween the appertaining bus bar and the phase outlet terminal, andmeans including a gas line arrangement connecting a plurality of saidchambers containing said related operating components in series toprovide a gas flow therethrough in one direction from a commonpressurized gas supply source.

2. A multi-phase, pressure-gas insulated, metal-enclosed switchgearplant as defined in claim 1 wherein the series connected chambers ofeach phase outlet containing said related operating components aresupplied withgas through separate gas lines connected respectively tosaid gas supply source.

3. A multi-phase, pressure-gas insulated, metal-enclosed switchgearplant as defined in claim 1 wherein the series connected chambers ofeach phase outlet containingsaid related operating components aresupplied with gas from said gas supply source through a gas line commonto all of said phase outlets.

4. A multi-phase, pressure-gas insulated, metal-enclosed switchgearplant as defined in claim 3 wherein a first set of chambers of the phaseoutlets containing related operating components which have the samefunction are directly connected together in series whereby the gas flowis directed therethrough prior to next being passed through a second setof directly connected chambers of the phase outlets which containrelated operating components having the same function.

5. A multi-phase, pressure-gas insulated, metal-enclosed switchgearplant as defined in claim 1 wherein said gas line arrangement connectingsaid chambers in series includes one-way valves which maintain the gasflow therethrough in the desired direction.

6. A multi-phase, pressure-gas insulated, metal-enclosed switchgearplant as defined in claim I wherein said gas line arrangement connectingsaid chambers in series is connected to said gas supply source throughsaid gas-pressurized chamber containing the phase bus bars.

7. A multi-phase, pressure-gas insulated, metal-enclosed switchgearplant as defined in claim 1 wherein said gas line arrangement includes agas flow indicator for determining the rate of gas flow through theseries connected chambers.

8. A multi-phase', pressure-gas insulated, metal-enclosed switchgearplant as defined in claim 1 and which further includes a gas circulatingplant including a pump, filter and de-humidifier connected by said gasline arrangement to said series connected chambers for effectingcirculation of gas through the chambers.

9. A multiphase, pressure-gasinsulated, metal-enclosed switchgear plantas defined in claim 1 wherein said gas line arrangement includesconnection points for a mobile plant including a pump, filter andde-humidifier by which to circulate the gas through said seriesconnected chambers.

10. A multi-phase, pressure-gas insulated, metal-enclosed switchgearplant as defined in claim 1 wherein the power circuit breaker for eachphase is of the gas blast type having a gas circuit closed over separatehigh and low pressure parts and wherein the high pressure part and thelow pressure part of the gas blast switch have respective gas circuitsindependent of the gas circuits which pass through the series connectedchambers containing said related operating components.

11. A multi-phase, pressure-gas insulated, metal-enclosed switchgearplant as defined in claim 1 wherein the series connected chambers ofeach phase outlet containing said related operating components aresupplied with gas from said gas supply source through a gas line commonto all of said phase outlets, a firstset of chambers of the phaseoutlets containing related operating components which have the samefunction being directly connected together in series whereby the gasflow is directed therethrough prior to next being passed through asecond set of directly connected chambers of the phase outlets whichcontain related operating components having the same function, and flowrestriction means interposed between the first and second sets of seriesconnected chambers such that upon occurrence of a sudden difference ingas pressure between said first and second sets of series connectedchambers equalization of the gas pressures therein is effected with adelay.

1. A multi-phase, pressure-gas insulated, metal-enclosed switchgearplant comprising a metal-enclosed gas-pressurized chamber for the busbar of each phase, single phase outlets electrically connectedrespectively to the corresponding phase bus bar, each said outletcomprising a row of metal-enclosed gaspressurized chambers containingrespectively the power circuit breaker for the phase and relatedoperating components such as an isolating switch, voltage transformerand cable and ground connections and which are seriately cOnnectedbetween the appertaining bus bar and the phase outlet terminal, andmeans including a gas line arrangement connecting a plurality of saidchambers containing said related operating components in series toprovide a gas flow therethrough in one direction from a commonpressurized gas supply source.
 2. A multi-phase, pressure-gas insulated,metal-enclosed switchgear plant as defined in claim 1 wherein the seriesconnected chambers of each phase outlet containing said relatedoperating components are supplied with gas through separate gas linesconnected respectively to said gas supply source.
 3. A multi-phase,pressure-gas insulated, metal-enclosed switchgear plant as defined inclaim 1 wherein the series connected chambers of each phase outletcontaining said related operating components are supplied with gas fromsaid gas supply source through a gas line common to all of said phaseoutlets.
 4. A multi-phase, pressure-gas insulated, metal-enclosedswitchgear plant as defined in claim 3 wherein a first set of chambersof the phase outlets containing related operating components which havethe same function are directly connected together in series whereby thegas flow is directed therethrough prior to next being passed through asecond set of directly connected chambers of the phase outlets whichcontain related operating components having the same function.
 5. Amulti-phase, pressure-gas insulated, metal-enclosed switchgear plant asdefined in claim 1 wherein said gas line arrangement connecting saidchambers in series includes one-way valves which maintain the gas flowtherethrough in the desired direction.
 6. A multi-phase, pressure-gasinsulated, metal-enclosed switchgear plant as defined in claim 1 whereinsaid gas line arrangement connecting said chambers in series isconnected to said gas supply source through said gas-pressurized chambercontaining the phase bus bars.
 7. A multi-phase, pressure-gas insulated,metal-enclosed switchgear plant as defined in claim 1 wherein said gasline arrangement includes a gas flow indicator for determining the rateof gas flow through the series connected chambers.
 8. A multi-phase,pressure-gas insulated, metal-enclosed switchgear plant as defined inclaim 1 and which further includes a gas circulating plant including apump, filter and de-humidifier connected by said gas line arrangement tosaid series connected chambers for effecting circulation of gas throughthe chambers.
 9. A multi-phase, pressure-gas insulated, metal-enclosedswitchgear plant as defined in claim 1 wherein said gas line arrangementincludes connection points for a mobile plant including a pump, filterand de-humidifier by which to circulate the gas through said seriesconnected chambers.
 10. A multi-phase, pressure-gas insulated,metal-enclosed switchgear plant as defined in claim 1 wherein the powercircuit breaker for each phase is of the gas blast type having a gascircuit closed over separate high and low pressure parts and wherein thehigh pressure part and the low pressure part of the gas blast switchhave respective gas circuits independent of the gas circuits which passthrough the series connected chambers containing said related operatingcomponents.
 11. A multi-phase, pressure-gas insulated, metal-enclosedswitchgear plant as defined in claim 1 wherein the series connectedchambers of each phase outlet containing said related operatingcomponents are supplied with gas from said gas supply source through agas line common to all of said phase outlets, a first set of chambers ofthe phase outlets containing related operating components which have thesame function being directly connected together in series whereby thegas flow is directed therethrough prior to next being passed through asecond set of directly connected chambers of the phase outlets whichcontain related operating components having the same function, and flowrestriction means interposed between the first and second sets of seriesconnected chambeRs such that upon occurrence of a sudden difference ingas pressure between said first and second sets of series connectedchambers equalization of the gas pressures therein is effected with adelay.